According to Eleonore Stump, Thomas Aquinas rejects a “popular” (roughly, penal substitutionary) account of the atonement. For Stump’s Aquinas, God does not require satisfaction or punishment for human sin, and the function of satisfaction is remedial, not juridical or penal. Naturally, then, Aquinas does not, on this reading, see Christ’s passion as having saving effect in virtue of Christ substitutionally bearing the punishment for human sin that divine justice requires. I argue that Stump is incorrect. For Aquinas, divine justice does (...) require satisfaction; satisfaction involves punishment ( poena) and has a penal function; and one way Christ’s death has saving effect is in virtue of his satisfying that requirement on people’s behalf. Christ saves by “paying our debt,” bearing in the place of humans the penalty or punishment required by divine justice. My argument implies that Aquinas’s account of satisfaction in the atonement significantly resembles key aspects of Stump’s “popular account”—and of the Penal Substitution Theory it represents. (shrink)